Rock Identifier

Category

Igneous Rock (Volcanic Glass)

Browse igneous rock (volcanic glass) specimens identified by the Rock Identifier community.

Learn about Igneous Rock (Volcanic Glass) in the encyclopedia

Rock Gypsum

Coral Rock

Asphalt Rock

Rock Salt

Calc-Silicate Rock

Calc-Silicate Rock

Talc-carbonate Rock

Talc-carbonate Rock

Black Obsidian

Obsidian

Pink Obsidian

Sideromelane

Carbonatite

Tachylite

Obsidian (Volcanic Glass (SiO2, usually 70% or more)) — igneous

Obsidian

Volcanic Glass (SiO2, usually 70% or more)

Pumice (Pumice (volcanic glass with vesicular texture)) — igneous

Pumice

Pumice (volcanic glass with vesicular texture)

Likely basalt or vesicular volcanic rock (Basalt, possibly scoriaceous basalt; exact identification is uncertain from the photograph) — igneous

Likely basalt or vesicular volcanic rock

Basalt, possibly scoriaceous basalt; exact identification is uncertain from the photograph

Amethyst-rich vesicular volcanic rock (probable amethyst basalt/scoria) (Quartz (SiO₂) in vesicular basaltic volcanic rock; precise identification requires testing) — igneous

Amethyst-rich vesicular volcanic rock (probable amethyst basalt/scoria)

Quartz (SiO₂) in vesicular basaltic volcanic rock; precise identification requires testing

Obsidian (Obsidian (Volcanic Glass, SiO2 + impurities)) — igneous

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Snowflake Obsidian (Volcanic glass with Cristobalite inclusions (70–75% SiO2)) — igneous

Snowflake Obsidian

Volcanic glass with Cristobalite inclusions (70–75% SiO2)

Obsidian (Volcanic Glass (Amorphous Silicon Dioxide)) — igneous

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Quartz Vein in Host Rock (Silicon Dioxide (SiO2) within Sedimentary or Igneous Matrix) — igneous

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Sedimentary or Igneous Matrix

Pumice (Extrusive volcanic rock (Vesicular Rhyolite/Dacite/Andesite)) — igneous

Pumice

Extrusive volcanic rock (Vesicular Rhyolite/Dacite/Andesite)

Pumice (Felsic Volcanic Glass / Vesicular Rhyolite) — Igneous

Pumice

Felsic Volcanic Glass / Vesicular Rhyolite

Red Scoria (Scoria (Vesicular Basalt)) — igneous

Red Scoria

Scoria (Vesicular Basalt)

Iron-stained Milky Quartz (Silicon Dioxide (SiO2) with iron oxide inclusions) — mineral

Iron-stained Milky Quartz

Silicon Dioxide (SiO2) with iron oxide inclusions

Obsidian (Obsidian (volcanic glass), amorphous SiO2 + impurities) — igneous

Obsidian

Obsidian (volcanic glass), amorphous SiO2 + impurities

Weathered mafic rock (probable basalt or gabbro fragment) (Basalt–gabbroic rock; chiefly plagioclase feldspar and pyroxene, possibly olivine) — igneous

Weathered mafic rock (probable basalt or gabbro fragment)

Basalt–gabbroic rock; chiefly plagioclase feldspar and pyroxene, possibly olivine

Basalt with Quartz Vein (Mafic volcanic rock with hydrothermal SiO2 filling) — igneous

Basalt with Quartz Vein

Mafic volcanic rock with hydrothermal SiO2 filling

Pumice (Vesicular volcanic glass (primarily SiO2)) — igneous

Pumice

Vesicular volcanic glass (primarily SiO2)

Basalt (Mafic extrusive igneous rock) — igneous

Basalt

Mafic extrusive igneous rock

Vesicular Basalt (Lava Rock) (Vesicular Basalt) — igneous

Vesicular Basalt (Lava Rock)

Vesicular Basalt

Basalt with Quartz Vein (Basalt with silicon dioxide (SiO2) inclusion) — igneous

Basalt with Quartz Vein

Basalt with silicon dioxide (SiO2) inclusion

Basalt (Weathered) (Mafic Igneous Rock) — igneous

Basalt (Weathered)

Mafic Igneous Rock

Basalt (Extrusive Igneous Rock) — igneous

Basalt

Extrusive Igneous Rock

Basalt (Porphyritic Basalt) (Extrusive Igneous Rock) — igneous

Basalt (Porphyritic Basalt)

Extrusive Igneous Rock

Pumice (Pumice (Vesicular intermediate to felsic volcanic glass)) — igneous

Pumice

Pumice (Vesicular intermediate to felsic volcanic glass)

Porphyry (Porphyritic Basalt / Andesite) (Porphyritic Igneous Rock) — igneous

Porphyry (Porphyritic Basalt / Andesite)

Porphyritic Igneous Rock

Basalt Pebble (Mafic Igneous Rock) — igneous

Basalt Pebble

Mafic Igneous Rock

Vesicular Basalt (or Rhyolite) (Extrusive Igneous Rock with Vesicular Texture) — igneous

Vesicular Basalt (or Rhyolite)

Extrusive Igneous Rock with Vesicular Texture

Basalt (Polished River Stone) (Aphanitic Mafic Igneous Rock) — igneous

Basalt (Polished River Stone)

Aphanitic Mafic Igneous Rock

Weathered volcanic rock, likely andesite or basalt (Fine-grained mafic to intermediate volcanic rock; probable andesite–basalt, compositionally dominated by plagioclase with pyroxene and possibly alteration minerals) — igneous

Weathered volcanic rock, likely andesite or basalt

Fine-grained mafic to intermediate volcanic rock; probable andesite–basalt, compositionally dominated by plagioclase with pyroxene and possibly alteration minerals

Obsidian (Obsidian (Volcanic Glass, complex silicate)) — igneous

Obsidian

Obsidian (Volcanic Glass, complex silicate)

Vesicular Basalt (or Scoria) (Extrusive Igneous Rock (Mafic)) — igneous

Vesicular Basalt (or Scoria)

Extrusive Igneous Rock (Mafic)

Clear Quartz (Rock Crystal) (Silicon Dioxide (SiO2)) — mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Obsidian (Volcanic Glass (Amorphous Silicon Dioxide)) — igneous

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Obsidian (Obsidian (volcanic glass, amorphous silica rich rock)) — Igneous

Obsidian

Obsidian (volcanic glass, amorphous silica rich rock)

Chalcedony (Agate) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Agate)

Silicon Dioxide (SiO2)

Greenstone (Chert) (Microcrystalline Silica (SiO2) with chlorite/epidote inclusions) — metamorphic

Greenstone (Chert)

Microcrystalline Silica (SiO2) with chlorite/epidote inclusions

Peridotite (Olivine-bearing Xenolith) (Peridotite (predominantly Forsterite Olivine, Mg2SiO4)) — igneous

Peridotite (Olivine-bearing Xenolith)

Peridotite (predominantly Forsterite Olivine, Mg2SiO4)

Snowflake Obsidian (Vitreous Volcanic Rock (Amorphous Silicate), SiO2) — igneous

Snowflake Obsidian

Vitreous Volcanic Rock (Amorphous Silicate), SiO2

Dark volcanic sand / basaltic sand (Basalt-derived lithic sand, chiefly plagioclase, pyroxene, and volcanic glass) — igneous

Dark volcanic sand / basaltic sand

Basalt-derived lithic sand, chiefly plagioclase, pyroxene, and volcanic glass

Basalt with Olivine and Scoria (Extrusive Igneous Rock) — igneous

Basalt with Olivine and Scoria

Extrusive Igneous Rock

Probable weathered basalt or andesite (Fine-grained mafic to intermediate volcanic rock; commonly plagioclase ± pyroxene, amphibole, and iron oxides) — igneous

Probable weathered basalt or andesite

Fine-grained mafic to intermediate volcanic rock; commonly plagioclase ± pyroxene, amphibole, and iron oxides

Obsidian (likely snowflake-free black volcanic glass) (Volcanic glass; predominantly rhyolitic silica melt (SiO₂-rich, noncrystalline)) — igneous

Obsidian (likely snowflake-free black volcanic glass)

Volcanic glass; predominantly rhyolitic silica melt (SiO₂-rich, noncrystalline)

Vesicular basalt (possibly scoria) (Basalt; chiefly plagioclase feldspar, pyroxene, and often olivine, with volcanic glass) — igneous

Vesicular basalt (possibly scoria)

Basalt; chiefly plagioclase feldspar, pyroxene, and often olivine, with volcanic glass